An apparatus for superimposing an image represented in a predetermined dot arrangement on a video signal. The apparatus includes inputting device (38), a memory (24), a storage block selecting device (40) and a signal switching circuit (32). The memory (24) has an arrangement of a plurality of storage blocks (102), each of which includes an arrangement of a plurality of unit storage cells (104) each for storing one bit. The inputting device (38) inputs externally prepared binary signals. The storage block selecting device (40) selects a predetermined storage block (102) for every inputted bit information. All the unit storage cells (104) in the selected storage block (102) store the inputted bit information. The signal switching device (32) sequentially reads the contents stored in each unit storage cell (104) in synchronization with a video signal, switches the video signal and a predetermined superimposing video signal to each other in accordance with the contents and outputs the same. As a result, each dot represented by the inputted binary information is represented by a plurality of dots in the reproduced video signal after being superimposed. The signal represented by the inputted binary information is reproduced on a picture frame as an expanded image.